Migrate from MathUtil::inverse() to gfx::Transform::GetInverse()

ui/gfx/transform.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include "ui/gfx/transform.h"
 
 #include <cmath>
@@ skipping 227 matching lines @@
       cofactor_part_5 -
       cofactor_part_6;
 
   // Technically the transformed z component is cofactor33 / determinant.  But
   // we can avoid the costly division because we only care about the resulting
   // +/- sign; we can check this equivalently by multiplication.
   return cofactor33 * determinant < 0;
 }
 
 bool Transform::GetInverse(Transform* transform) const {
-  return matrix_.invert(&transform->matrix_);
+  if (!matrix_.invert(&transform->matrix_)) {
+    // Initialize the return value to identity if this matrix turned
+    // out to be un-invertible.
+    transform->MakeIdentity();
+    return false;
+  }
+
+  return true;
 }
 
 void Transform::Transpose() {
   matrix_.transpose();
 }
 
 void Transform::TransformPoint(Point& point) const {
   TransformPointInternal(matrix_, point);
 }
 
@@ skipping 124 matching lines @@
       matrix_.getDouble(2, 1),
       matrix_.getDouble(2, 2),
       matrix_.getDouble(2, 3),
       matrix_.getDouble(3, 0),
       matrix_.getDouble(3, 1),
       matrix_.getDouble(3, 2),
       matrix_.getDouble(3, 3));
 }
 
 }  // namespace gfx